Many applications require the use of lock nut arrangements for permitting a fixed positional relationship to be established between a threaded rod and an object or article. The conventional lock nut arrangement involves threading a first nut along the rod until reaching a position of abutting or stationary engagement with the article, and threading a second nut along the rod until it snugly abuts the first nut so as to prevent loosening of the latter. This conventional arrangement, which having been utilized for many years, nevertheless possesses well-recognized disadvantages. For example, this arrangement requires the use of two separate nuts. Further, each nut must be threaded along, in many instances, a very long axial extent of the threaded rod before reaching the desired locking position. This is obviously a laborious and time consuming operation, and in many instances it is impossible to provide proper access for the nuts on the rod, particularly in situations where the lock nuts are desired for disposition on an intermediate section of the rod.
In an attempt to provide an improved lock nut arrangement, variations have been devised which involve the use of a nut employing a captive spring, such as a gripping spring or the like. Such springs are intended to create a gripping engagement between the object and the nut, and to maintain sufficient tension to prevent loosening of the nut. Such arrangements, however, have also possessed similar disadvantages since they must be threaded over the free end of the rod and then threaded to the position of use.
Others have made two-piece lock nuts which would be installed transversely on a section of threaded rod. These devices, however, were commercially impractical since the two nuts were confusingly similar when separated. Such devices, are shown in Rox, U.S. Pat. No. 2,355,679. Others have used a single C-shaped nut as shown in Rox, U.S. Pat. No. 2,374,309 and DeLong, U.S. Pat. No. 1,375,781. However these devices unevenly load the rod threads and must rely on function or a C-shaped washer to prevent radial disengagement.
Accordingly, it is an object of this invention to provide an improved lock nut arrangement which overcomes the disadvantages associated with the conventional arrangements as briefly described above.
More specifically, it is an object of this invention to provide an improved lock nut arrangement which can be moved transversely into engagement with a threaded rod closely adjacent the desired position of use, whereby it is unnecessary to thread the lock nut arrangement onto the rod over the free end thereof.
A further object and advantage of this improved lock nut arrangement is its ability, when positioned on the threaded rod, to be moved into a locking position by relative rotation with respect to the rod of less than one revolution.
A further object of the invention is to provide an improved lock nut arrangement and method for making same which, in addition to the advantages explained above, is constructed of two nuts which are permanently joined together by a connection which permits relative rotation and limited axial displacement between the two nuts, whereby there is provided an integrated and unitary assembly which can be consistently manufactured and used in a manner similar to a single nut.
It is further an object of this invention to provide a method for simply making lock nut arrangements so that the two lock nut portions consistently locked on the shaft with proper orientation.
Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawings.